转：《到底有多少只脚？》

There is a bus with 7 girls.

Each girl has 7 bags.

In each bag, there are 7 big cats.

Each big cat has 7 little cats.

Each cat has 4 legs .

Question: How many legs are present in the bus? (cats or girls - think carefully)

虽然设定有点匪夷所思，但是猜一猜无妨。
所以？到底有多少只脚呢？